*{
    margin: 0;
    padding: 0;
     list-style: none;
}
.nav{
    width: 1200px;
    height: 50px;
    margin: 0 auto;
    background: black;
}
.nav>li{
    float: left;
    color:#fff;
    line-height: 50px;
    margin-left: 30px;
}
.nav>p{
    float: right;
    color:#fff;
    margin-right: 40px;
    line-height: 50px;
}
.nav1{
    width: 1200px;
    height: 80px;
    margin: 0 auto;
    background: lightcyan;
}
.q1{
    width: 50px;
    height: 50px;
    float: left;
    background:  url(http://localhost:3000/img/1.png);
    background-size: 100% 100%;
    margin-top: 15px;
    margin-left: 30px;
}
.q1:hover{
    width: 50px;
    height: 50px;
    float: left;
    background:  url(http://localhost:3000/img/2.png);
    background-size: 100% 100%;
    margin-top: 15px;
    margin-left: 30px;
}
.nav1>li{
    float: left;
    line-height: 80px;
    margin-left: 40px;
}
.nav1-input{
    float: right;
    margin-top:25px;
    margin-right: 100px;
}
.nav1-input>input{
    height: 30px;
    float: left;
    padding-left: 10px;
}
.nav1-input>p{
    width: 30px;
    height: 32px;
    text-align: center;
    line-height: 30px;
    float: left;
    background: #fff;
    border: 1px solid  lightslategray;
}
.nav3{
    width: 1200px;
    height: 80px;
    background: lightyellow;
    margin: 0 auto;
}
.nav3 li{
float: left;
line-height: 80px;
margin-left: 40px;
color:lightsteelblue
}
.span{
    margin-left: 30px;
}
.content{
    width: 1200px;
    height: 450px;
    margin: 0 auto;
}